Stripping tang nuts, suggestions?

T

TroyO

Joined
Mar 20, 2001
Messages
71
I am re-fitting a handle on a short sword, and I had a question on hardening the brass for the tang nut.

I have been drilling a 15/64ths hole in a chunk of barstock, and tapping for 1/4x20 (The threads on the tang.) then chucking it up in a drill press and filing the thing round. Is that drill too big for the thread size, maybe?

It seems the threads give out really easy, is there a way to harden the brass so it holds up better? I can't get the thing very tight before it strips out. I seem to remember that you can harden brass by heating it to red, and then cooling slowly. Is air cooling slow enough to get this to work, or do I need to let it cool in vermeculite (sp) or something?

I am only using a 4 inch pair of needle nose vice grips with a piece of leather between the jaws to tighten it, so I don't think it is excessive. I also brazed over and re-threaded the end of the tang (Screwed up threads banging out the glued handle.) and that side doesn't seem any worse for the wear.

Any suggestions? Am I missing something basic?

Thanks!
Troy
 
Troy,

I have done several of the threaded tang knives with threaded brass pommels, I drill as deep as possible into the pommel with a 1/16" smaller drill bit then the tang size. 3/16" hole for a 1/4" tang size this leaves really deep threads,just be sure the tang threads are good and deep and not badly worn, I've put the handle in a vise and tightened with padded vise grips and never had any problems.(knock on wood)
Hope this helps
Bill
 
Are you using a bottoming tap?If not,the threads may not be going down far enough.If you dont have a local source for one,just grind the tapered tip off a regular tap.You are right about hardening brass.Heat it red hot and let it air cool,dont know about slower cooling though.Sorry I cant be of more help.
 
I all else fails try getting a piece of steel tubing with the correct size inside diameter and silver brave a piece that is about a half inch long in the brass then tap this,or you can get threaded extension nuts for a 1/4 X 20 bolt and you can inset a piece of that in the brass and silver braze that in.Tis will give the threads the toughness of the steel and the looks of the brass.
Bruce
 
find a small high speed bearing, and a block of wood that will span your drill press table. counter bore the outer race of the bearing into wood, so that the inner race is clear. drop a smooth headed bolt through thehole in the inner race and push this up tight against the bottom of the brass making sure it is centered. if you cut a piece of tubing, so that the jaws of your chuck are tight to the tube, which pushes tight to the brass being worked, that is supported by the bolt, that is centered in the bearing set in the wooden block clamped to the drill press table.

check the set up. First by hand, then by turning it on momintarily. then at slow speed.

set the lever stops to keep this set up under pressure.

you have now changed your drill press into an upright lathe, the bolt is a live center. as long as you keep the tension on the bolt/bearing, you are removing tension from the threads inside the buttplate:D
 
Thanks guys, it ended up being a slew of little things... I drilled a bit smaller hole (3/16.. I was using 13/64th, not the 15/64th I posted earlier.)

I also figured out that the butt cap was binding up against the tang, keeping the whole assembly from tightening up, which with my usual motto of "Brute force can overcome design and engineering any day!" I responded to by cranking it down a bit harder.... I guess you can generate a bit of tourque with a small pair of vice grips and a hunk of leather. ;-P

Anywaw, with longer threads, a smaller hole, freeing up the butt cap, and hardening the brass with a torch everything is working well.

It goes "schhhing" instead of "clunk" during the tap test, now!

Its a KrisCutlery Baselard, re-fitted the handle (It was just black cotton wrap) with a leather/wire wrap and made a felt lined, leather wrapped wood scabbard for it.


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